Abstract: Objective To investigate the DNA polymorphism of Pseudallescheria boydii and Scedosporium apiospermum and to analyze the relationship between random amplification of polymorphic DNA (RAPD) patterns and geographic origins.Methods The genomic DNAs of 13 Pseudallescheria boydii strains and 18 Scedosporium apiospermum strains isolated from 5 countries were amplified with RAPD technique.Results All strains tested were classified into 31 patterns by combination of the results obtained with 3 primers.The cluster tendency was identified based on species difference,namely,P.boydii or S.apiospermum strains,however,no such cluster tendency was revealed based on geographic origins of the most of strains,by dendrogram analysis.Conclusions The infraspecific variability of P.boydii and S.apiospermum is considerable.The cluster tendency of RAPD profiles is of consistency with morphological properties of P.boydii and S.apiospermum to some degree,however,is of no correlation with geographic origins of the pathogenic strains.

Key words: Pseudallescheria, Scedosporium, Random amplified polymorphic DNA technique